This has been the best kitchen-sink SEO plugin for many years with a wealth of options and data available within a few clicks. It's good by itself but even more useful if you are a regular user or subscriber of SEMrush as there is a tonne of data. I can only give it 4 stars as I think some of the UX could be improved, and perhaps the overall data refined to make it slightly less overwhelming to new users. Overall decent extension and a must have for Firefox SEOs.